Finding the perfect bra can be about as easy for women as it is for men to undo one.

A woman's boobs change size six times throughout her life and it's common to find the same girl coming up a different size in each store or label.

That confusion can mean accurately estimating your own size is almost impossible.

Some women use fitting room trial and error to get a look they like, while others book an appointment for a proper fitting from an expert.

But despite the amount of options on offer, a staggering amount of British women still wear the wrong size bra every day - and it could be doing you damage.

To help women everywhere, we’ve taken a look at some stats to show estimation is no replacement for an accurate bra fitting. And below we've created a quiz to reveal if your bra size might be miles off...

Scroll down to take the quiz!

How many women guess and get it wrong?

Bra fit isn't the most important factor for buyers (Image: Getty)

Two-thirds of women wear the wrong bra size, a recent poll found. And of those, almost a third purchased their bra knowing it wasn’t the right fit.

The most common combination of errors is to wear an over-sized back size with a cup size that is too small, according to bra brand Freya.

How many estimate their size rather than get a fitting?

Italian women are the biggest fans of fittings (Image: Getty)

Just 37% of women in the UK have been for a professional fitting. Italian women top the table with 64% attending, compared with 42% of the French, 35% of Americans and just 25% of Germans.

Luxury chain Rigby and Peller - who supply bras to the Queen and Kim Kardashian no less - have introduced a 3D bra fitting mirror which scans your body and recommends the best bra for your shape to take the guess work out of it. But it's only available at its London and Hong Kong stores.

Women in UK are the biggest self-sizers

By analysing Google search trends dating back to 2004 we can see that UK users top the global charts for the term 'bra calculator.'

The UK is also top for the alternative searches of 'measure for bra' and 'bra measuring' - suggesting UK women are more likely to estimate their bra size, than have a fitting.

With so many sizes and styles, it's easy to guess wrongly

The experts at the Ultimatebraguide.com list more than 20 different types of bra on the market. They include designs such as the Balconette, Demi cup, Push-up and Minimiser.

Where and when you’re born can help you predict your natural size - as well as what you drink

Women in Cheshire, Manchester and Lancashire have the largest boobs with an average DD, according to The Great British Bra Survey. Those in the North East, including Newcastle, had the smallest, averaging a B cup.

Women in Wales and the Midlands are bang in the middle, averaging a C cup, while the average size in Scotland is 36DD.

In terms of when you were born, those with birthdays in January, February and March are more likely to have bigger boobs - with an E cup average. But if you’re born in April, that figure drops down to a B cup.

Drinking coffee can apparently make your boobs smaller

Ds and DDs are the average for those born in June, July and November, while the rest of the months average a C.

Your choice of cuppa also apparently plays a part. Drinking coffee can actually make your boobs smaller, a British Journal of Cancer study found. Just three a day is enough to make a difference. They reckon half of women have a specific gene which links the two.

What sort of damage might you be doing to yourself by estimating your bra size?

The wrong bra can be a right pain (Image: Getty)

Well, lots. The Chartered Society of Physiotherapy says that women wearing the wrong size bra are risking nerve damage, poor posture and pains in their neck, shoulder and back - plus saggy boobs.